Opiate alkaloids are important pharmaceuticals for a variety of purposes. “Nal”-opiates are a class of alkaloids containing tertiary amines which includes, among others, α- or β-naloxol. Nal-opiates share a basic morphinan chemical structure and include a tertiary amine at the N-17 position. They are particularly useful as competitive antagonists of opioid compounds, and as such are widely used in treating substance abuse and addiction.
Production of nal-opiates generally proceeds through a number of synthetic steps, where each step requires isolation of the intermediate before the next synthetic step can be performed. Isolation becomes necessary for a number of reasons, including because byproducts of the reaction interfere with later synthetic steps which may lower the yield or halt the reaction altogether. Moreover, isolation of intermediates itself is an extra synthetic step that can lower the yield and efficiency of the total synthesis. For example, some syntheses require that intermediates be purified through a number of steps so that the remainder of the reaction can proceed in high yield.
Thus, there is a need for routes to nal-opiates which do not require the isolation of intermediates.